Petra Nemcova recalled the "split seconds" before the 2004 tsunami in Thailand changed her life forever.

Nemcova, now 45, had been vacationing during the Christmas holiday with her then-boyfriend and photographer Simon Atlee in Thailand when a 9.5-magnitude earthquake off the coast of Indonesia caused the world's worst tsunami. The supermodel had been packing on Dec. 26, 2004, after spending a peaceful morning with Atlee on the last day of their vacation.

However, with two hours left until the two would head to the airport, screams from guests at the pool startled Nemcova.

"Everything happened in split seconds," she told People magazine. "I looked up to see frantic movement and people jumping and then in the next second, the wave is crashing into the bungalow and breaking all of the glass windows."

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Petra Nemcova poses for a modeling shot

Petra Nemcova recalled surviving the 2004 Boxing Day Tsunami in a new interview. (Edward Berthelot/Getty Images)

Nemcova recalled her last moment with Atlee as shards of glass cut into her.

"I heard Simon screaming my name, and it was the last time I heard him."

The model tried to hold on but eventually "let go."

"At some point, I couldn't breathe anymore. And I thought, 'That's it.' That's my last moment. And I let go. And actually, it was the most blissful moment of my life," Nemcova explained.

"And then, by some miracle, I was able to see sky again."

Nemcova instinctively grabbed onto a palm tree, where she clung for "an incredibly long eight hours" with a broken pelvis.

She couldn't feel or move her legs at the time as she listened to the screams of children.

"Half an hour later, I couldn't hear them anymore," Nemcova told People. "And that meant that they couldn't hold on. I couldn’t swim out [to them] because I was trapped by debris. That day, I couldn’t help. I had no choice."

Petra Nemcova sits on a panel

Petra Nemcova's boyfriend, Simon Atlee, did not survive the tsunami. (Jim Spellman/WireImage)

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Petra Nemcova posing on

The 2004 tsunami killed more than 200,000 people. Nemcova survived by clinging to a palm tree for "an incredibly long eight hours" with a broken pelvis. (Gisela Schober/Getty Images)

After surviving, Nemcova set out to give back. 

She created the Happy Hearts Fund in 2005 as a way to rebuild schools in areas hit by natural disaster.

"Hearing children screaming for help and not being able to help them, that leaves such a powerful mark," Nemcova explained. "Today and every day, I have a choice to help." 

Since 2005, Happy Hearts Fund has grown into All Hands and Hearts.

The organization will arrive in areas about to be affected by natural disasters to help prepare and then rebuild homes and schools in the aftermath, according to People magazine.

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Petra Nemcova attends an event in 2005

Petra Nemcova traveled back to Thailand in 2005. (R. Born/WireImage)

Nemcova traveled back to Thailand in 2005 to honor Atlee. The supermodel also chose to face her fear of the water head on by scuba diving during the trip.

"I went under the water, and I was panicking," Nemcova recalled to the outlet. "My heart was going so fast, and I just couldn't even breathe properly, but it's very important not to live in a life of any fear. That's why I did it."

She admitted it took a few years for "the sounds of palm leaves crashing onto the roof of a hotel or a bungalow" to not reignite her memories.

"And then it lost power over me," Nemcova explained. "If you appreciate the gift of air, if you appreciate the ability to move your legs, everything else is much richer. Your life is happier. You’re living instead of just surviving."

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